Fig. 1: A global assessment of field-based nitrogen (NUE) and phosphorus use efficiency (PUE) across four major crops (rice, wheat, maize, soybean).
From: Global-scale prevalence of low nutrient use efficiency across major crops
a The circular legend indicates the global distribution of the four major crops, where the overlap represents intercropping and rotational cropping. Crop plantation base map from SPAM 2010 V2r070. b The distribution of temperature and precipitation at the sample points. MAT, mean annual temperature; MAP, mean annual precipitation. Count represents the frequency of the collected samples under the same location and within similar climatic conditions. c The four colors of the crops are referenced to the global distribution of four major crops, distributed from top to bottom to represent rice, wheat, maize, and soybean. The letter M, SD, n refer to the mean value, standard deviation and count, respectively.
